Origin

The earliest meaning of clog was ‘a block of wood’, especially one fastened to the leg or neck of an animal to stop it moving too far. The term for a wooden-soled shoe is nearly as early and probably first referred to the thick wooden sole alone. The verb was first used to mean ‘to hamper something’, and from this developed the idea of hindering free passage through something by blocking it. Clogs were formerly worn by factory and manual workers in the north of England. From clogs to clogs in three generations is said to be a Lancashire proverb, meaning that it takes one generation to found a business, the next to build it, and the third to spend the profits, leaving the family penniless again.